Alison R. Taylor, Professor

Cell Biology of Marine Protists

Despite playing a pivotal role in our oceans, relatively little is known about the cell biology of marine protists, a large and diverse group of unicellular organisms which includes both autotrophic and heterotrophic groups. Research in my lab has focussed on the cell biology of diatoms and coccolithophores, two of the most significant groups of phytoplankton with respect to ocean primary productivity and marine biogeochemical cycles. This work has revealed that these organisms, regarded until recently to be essentially plant-like algae, possess a variety of animal-like membrane transport properties. This is supported by the recent availability of genome sequence data which confirms the presence of groups of animal-like genes including those for metabolism, ion channels and transporters. These genes have most likely been acquired from the heterotrophic ancestral host during the secondary endosymbiotic evolutionary origin of the heterokont lineage. To what degree such animal-like properties underpin the environmental physiology and contribute to the global success of these marine autotrophic protists is a driving question in our research. While a comparative approach among a range of phytoplankton and other heterotrophic marine protists is the longer-term goal of our research, work is currently centred on identifying and functionally characterising ion transport mechanisms associated with signalling and homeostasis in diatoms, coccolithophores and foraminifera. To address these questions we use a variety of conventional and novel cell physiology techniques including electrophysiology and high resolution imaging combined with molecular approaches. Current research includes the following topics: